A new study shows it would be possible for the Western power grid to draw 35 percent of its electricity from wind and solar energy sources by 2017. The Western Wind and Solar Integration Study, released by the U.S. Department of Energy’s National Renewable Energy Laboratory on May 20, examines the benefits and challenges of integrating wind power, solar photovoltaic systems, and concentrating solar power onto the grid. The study concludes that while additional infrastructure isn't needed, key operational changes are required to meet this target. The report focused on the power system operated by the WestConnect group of utilities in Arizona, Colorado, Nevada, New Mexico and Wyoming.
The study found that coordinated operations among utilities across a large geographic area decrease the effect of the variability of wind and solar energy sources. Though wind and solar output vary over time, the study shows that it is operationally possible to accommodate 30 percent wind and 5 percent solar energy penetration to the grid. To accomplish such an increase, utilities will have to schedule their generation deliveries, or sales, on a more frequent basis. Currently, generators provide a schedule for a specific amount of power they will provide in the next hour, a process called “hour ahead” scheduling. More frequent scheduling would allow generators to adjust that amount of power based on changes in system conditions, such as increases or decreases in wind or solar generation.
The study also finds that if utilities were to generate as much as 27 percent of their electricity from wind and solar energy across the Western Interconnection grid, it would lower carbon emissions by 25 to 45 percent, while decreasing fuel and emissions costs by some 40 percent, depending on the future price of natural gas. Other key findings from the study include: existing transmission capacity can be more fully utilized to reduce the amount of new transmission that needs to be built; to facilitate the integration of wind and solar energy, coordinating the operations of utilities can provide substantial savings by reducing the need for additional backup generation, such as natural gas-burning plants; and the use of state-of-the-art wind and solar forecasts in utility operations is essential for cost-effectively integrating these renewable energy sources. The study complements the previously released Eastern Wind Integration and Transmission Study, which examines the feasibility of integrating up to 30 percent wind in the Eastern states.
Reprinted from EERE Network News , a free newsletter from the U.S. Department of Energy.